In the digital video signal processing, generally the digital video signal will be encoded and compressed for the high-speed transmission in a bandwidth-limited channel. For example, MPEG is a block-based video compression format for the foregoing purpose.
After the encoding and compressing, the video signal is transmitted through the transmission channel to a decoder. The decoder decodes and decompresses the video signal. However, an annoying block border effect occurs after re-constructing the video signal by the decoder. A user can observe block borders since the source image signal is encoded on a block-by-block basis. Conventionally, a low pass filter is used to eliminate the block border effect; however, many details of image are lost.
Therefore it is desirable to have an adaptively de-blocking circuit and associated method